Metal Gear​ (メタルギア) is an overhead military action adventure game originally released in 1987 by Konami for the MSX2 computer standard in Japan and parts of Europe. Considered to be the progenitor of the stealth game genre, it was also the first video game designed by Hideo Kojima, who also directed many of the later Metal Gear sequels.A heavily altered port was produced for the Nintendo Entertainment System (without Kojima's involvement), along with a remade version based on the original MSX2 game that was released for the PlayStation 2 as a bonus game in Metal Gear Solid 3: Subsistence.

The game revolves around a special forces operative codenamed Solid Snake who goes into a solo infiltration mission into the fortified state of Outer Heaven to destroy Metal Gear, a bipedal walking tank capable of launching nuclear missiles from anywhere in the world.